Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=true, and the description meaningfully extends this: it discloses the 10,000-result pagination ceiling with mitigation advice, the German-time whole-day date semantics, and the underlying GET /v1/voucherlist endpoint. It does not describe response envelope shape, but the returned metadata fields are enumerated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Dense but front-loaded: the core purpose and return contents come first, then routing, then date/pagination constraints. It is long and paragraph-heavy, but nearly every clause carries information an agent needs to call the tool correctly, so little is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 15-parameter, zero-required filter tool with no output schema, the description covers purpose, defaults, date format/timezone, pagination limits, and downstream routing – enough to invoke it correctly. Minor gaps remain around result ordering guarantees and how the 10,000 cap interacts with next_page, but the essentials are present.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3; the description adds real semantic value on top by clarifying that omitted voucher_types/voucher_statuses mean 'all' and that dates are yyyy-mm-dd evaluated as whole days in German time. It does not restate enum nuance already documented in the schema (e.g. overdue exclusivity).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb+resource ('Search the voucher list'), enumerates the exact document and bookkeeping voucher types returned, and lists the metadata fields returned. It is clearly distinguishable from every sibling list/get tool because it explicitly maps each type to its corresponding lexware_get_* tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit filtering guidance ('Omit voucher_types / voucher_statuses for all') and a full when-to-use-the-alternative routing table (invoice → lexware_get_invoice, etc.). The recommendation to narrow dates when exceeding the 10,000-result cap is also actionable usage guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.